This study focuses on the reconfiguration of bus services in an urban area with a newly constructed rail system. A hub-and-spoke network framework is introduced for the multimodal transit system. The rail services are...
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This study focuses on the reconfiguration of bus services in an urban area with a newly constructed rail system. A hub-and-spoke network framework is introduced for the multimodal transit system. The rail services are taken as the backbone, and the bus services (main bus lines and feeder bus lines) are reconfigured to better integrate with rail services forming the core of a Mobility as a Service (MaaS). A cluster-based approach is used for selecting hubs from rail stations. Bus stops are taken as non-hub nodes. Main bus lines are designed based on a heuristic line generation approach and feeder bus lines are developed by solving a travelling salesman problem. A bi-levelprogramming model is proposed to determine frequencies of each mode and addressed by the artificial bee colony algorithm. The effectiveness of the proposed methods is illustrated by numerical examples and applied to the Mandl's benchmark compared with existing studies.
with the onboard diesel generators and energy storage system to meet the propulsion and service load, the all-electric ship (AES) can be viewed as a mobile microgrid'. Nowadays, photovoltaic (PV) generation is gra...
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with the onboard diesel generators and energy storage system to meet the propulsion and service load, the all-electric ship (AES) can be viewed as a mobile microgrid'. Nowadays, photovoltaic (PV) generation is gradually integrated into the AES for a greener' voyage. To fully utilise the PV energy, this paper proposes a joint generation and voyage scheduling method for the PV integrated AES. The overall model is formulated as a bi-level programming problem and solved by column-and-constraint generation method. The simulation results manifest that, the integration of PV into AES leads to reductions on both the fuel consumption and CO2 emission.
In this paper we addressed supply chain network (SCN) as bi-level programming problem in which the primary objective is to determine optimal order allocation of products where the customer's demands and supply for...
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In this paper we addressed supply chain network (SCN) as bi-level programming problem in which the primary objective is to determine optimal order allocation of products where the customer's demands and supply for the products are fuzzy. In the proposed SCN model, we suppose that the first level (leader) and second level (follower) operate two separate groups of SCN. The leader, who moves first, determines quantities shipped to retailers, and then, the follower decides his quantities rationally. The leader's objective is to minimize the total transportation costs, and similarly, the follower's objective is to minimize the total delivery time of the SCN and at the same time balancing the optimal order allocation from each source, plant, retailer and warehouse respectively. The fuzzy goal programming approach has been used to achieve the highest degree of the membership goals by minimizing the deviational variables so that most satisfactory or the preferred solution for both the levels to be obtained. A numerical example is given to demonstrate the proposed methodology.
This study attempts to optimize the operations of the Recycling Fund Management Board (RFMB), founded by the Environmental Protection Administration of the ROC Government (in Taiwan), by using a subsidy rate decision ...
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This study attempts to optimize the operations of the Recycling Fund Management Board (RFMB), founded by the Environmental Protection Administration of the ROC Government (in Taiwan), by using a subsidy rate decision for domestic printer recyclers. The hierarchical and interactive relation between the two parties is modeled by bi-levelprogramming, where the RFMB serves as the upper-level decision unit, recyclers are the lower-level counterpart, and the consumer's action is embedded in the constraints of the lower levelproblem. The problem is solved by the Karush-Kuhn-Tucker transformation approach. Practical data including sales of printers per year, a survey of recycling intention, recycler cost structure, and resource recycling value are used to solve the problem. The resulting solution discovers the inefficiency of the current operations of RFMB, and suggests an appropriate recycling fee and subsidy rate that balance the interests of printer manufacturers, recyclers, and the RFMB.
This study attempts to optimize the operations of the Recycling Fund Management Board (RFMB), founded by the Environmental Protection Administration of the R.O.C. Government (on Taiwan), through the decision of a subs...
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This study attempts to optimize the operations of the Recycling Fund Management Board (RFMB), founded by the Environmental Protection Administration of the R.O.C. Government (on Taiwan), through the decision of a subsidy rate for the domestic glass recycling industry. The hierarchical and interactive nature between the two parties is modelled by bi-levelprogramming, where the RFMB plays the upper-level decision unit while the recycling industry is the lower-level counterpart. In order to solve the problem by optimization software, the bi-level formulation is transformed to a single-levelproblem via Karush-Kuhn-Tucker optimality conditions and is further transformed to a 0-1 mixed integer programmingproblem by variable substitution. The problem is solved with real-world data, and the obtained solutions are analysed and compared with the RFMB's current operations. The results suggest that the proposed approach can improve the operations of the RFMB. Journal of the Operational Research Society (2012) 63, 28-37. doi:10.1057/jors.2011.13 Published online 30 March 2011
The purpose of this study is to determine the optimum subsidy rate for the glass recycling industry in *** hierarchical and interactive nature between the agency and the industry is modeled by bi-levelprogramming, wh...
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The purpose of this study is to determine the optimum subsidy rate for the glass recycling industry in *** hierarchical and interactive nature between the agency and the industry is modeled by bi-levelprogramming, where the agency plays the upper-level decision unit while the recycling industry is the lower-level *** order to solve the problem by optimization software,the bi-level formulation is transformed to a single levelproblem via Karush-Kuhn-Tucker(KKT) optimality conditions and is further transformed to a 0-1 non-linear programming *** problem is solved with real-world data,and the obtained solutions are analyzed and compared with current operations.
A key player in a supply chain (SC) is the member who overlooks and leads others. Although it can compel its autonomous members to follow the planning of a production-distribution network (PDN), the key player has to ...
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A key player in a supply chain (SC) is the member who overlooks and leads others. Although it can compel its autonomous members to follow the planning of a production-distribution network (PDN), the key player has to create an environment in which the partnership with suppliers can also grow accordingly. Without the effective partnership, the efforts increase in managing and integrating the information and material flow across the PDN. Hence, while designing the PDN, the key player has to consider the constraint of the autonomous suppliers also seeking maximum profits as their business goals. In addition, to alleviate the impact of uncertainty on the PDN of a global SC, the strategy of alternative design features is incorporated in the PDN design model. In this paper, the problem for key player's PDN design with alternative design features (KPDN/ADF) is formulated as a bi-level programming problem. An extended genetic algorithm is proposed to solve the KPDN/ADF problem. The experiment results showed that the proposed algorithm can solve the problem satisfactorily. Furthermore, incorporating the product design strategy of alternative design features can make the key player's PDN have better profit under the uncertainty of the currency exchange rate. An illustrative global SC of personal computers/notebooks is also provided to demonstrate the applicability of the KPDN/ADF design model.
All the elements of a transportation system model generally suffer from some approximation. Normally the demand vector is considered the most crucial and problematic element to be simulated, and traffic counts are thu...
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ISBN:
(纸本)9781845640873
All the elements of a transportation system model generally suffer from some approximation. Normally the demand vector is considered the most crucial and problematic element to be simulated, and traffic counts are thus generally used to update it so that the whole model system is able to reproduce the observed link flows. Updating demand vectors using traffic counts has received considerable attention in recent years. In this paper the methodology proposed by Cascetta and Postorino (Fixed point models for the estimation of O-D matrices using traffic counts on congested networks. Transportation Science, Vol. 35, 2001) for updating the demand vector using traffic counts on congested networks is applied to a real case: the OD demand vectors for the city of Naples (Italy). The results show the good capacity of this methodology to reproduce the traffic counts measured. Furthermore, through the estimated OD vectors it was possible to make a structural analysis of transportation demand in Naples.
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